Phase separator

ABSTRACT

A body providing an interior helical flow path for separation of fluid in the vapor phase from a flowing liquid stream. Separate passages lead from the flow path and from one end of the body and in one of these is venturi means exerting an eduction influence on the other passage.

United States Patent Fernandes et al.

PHASE SEPARATOR Inventors: Joseph F. Fernandes;

Coolidge, both of Dayton, Ohio Assignee: United Aircraft Dayton, OhioFiled: March 18, 1970 Appl. No.: 20,626

Products,

Anson S.

Inc.,

[ Aug. 29, 1972 [56] References Cited UNITED STATES PATENTS 3,561,5032/1971 Rogge ..141/59 Primary Examiner-H0ust0n S. Bell, Jr. Attorney].E. Beringer [57] ABSTRACT A body providing an interior helical flow pathfor separation of fluid in the vapor phase from a flowing liquid stream.Separate passages lead from the flow path and from one end of the bodyand in one of these is venturi means exerting an eduction influence onthe other passage.

1 1 Claims, 2 Drawing Figures REL.

l /r I as TM PATENTEflAuszs I972 FIG-l 23 THE/R ATTORNEY BACKGROUND OFTHE INVENTION This invention relates to a device separating a twophasefluid into liquid and gas components. Although not so limited, it hasspecial reference to liquid containers and particularly to meansallowing the rapid filling of such containers with a saturated liquid.In a specific embodiment, the invention deals with the problem offilling containers with cryogenic fluids, that is, with oxygen, liquidhydrogen or the like, rapidly and without excessive loss byvaporization. In the pertaining fluid handling art, cryogenic fluids aretaken from bulk storage and transferred to double walled vessels knownas dewars, by which they may expeditiously be transported to a place ofuse and selectively drawn upon as needed. The cryogenic fluid reachesthe dewar in an essentially two phase form, substantial amounts of vaporbeing liberated from the liquid due to warming and pressure decrease. Avapor outlet from the dewar provides for escape of gases after they havereached the dewar and after they have risen to the upper part thereof.This is a relatively slow process, however, so that filling of the dewarwith a saturated liquid has heretofore been slow and has beenaccompanied by excessive vapor loss.

The instant invention has in view a combined inletoutlet fittingconstructed to promote phase separation before the cryogenic fluidreaches the dewar interior. The liquid entering the dewar accordinglyflows at a higher mass flow rate. The filling time is reduced and theamount of vapor phase fluid lost to the vent outlet is reduced. In anoptional feature of the invention, the separated vapor phase fluidescapes through means utilizing the flow thereof to evacuate the upperpart of the dewar interior. Vapors released within the dewar are therebywith greater facility conducted to the vent outlet.

An object of the invention is to provide means of general utilityremoving gas from a flowing stream comprising liquid and gas.

Another object of the invention is to provide separator means allowingrapid filling of closed containers with saturated liquid.

A further object of the invention is to provide a device which can beinstalled on new or existing dewars and like vessels for a rapid fillingthereof with minimum vapor loss.

Other objects and structural details of the invention will appear fromthe following description, when read in connection with the accompanyingdrawings, wherein:

F IG. 1 is a partly diagrammatic view of a device in accordance with theinstant invention shown applied to a dewar for the handling of cryogenicfluids; and

F16. 2 is a detail, fragmentary view showing a valve in the device ofFIG. 1 in an open position.

Referring to the drawings, the invention is disclosed in a systemhandling cryogenic fluids. In such systems, a cryogenic fluid such asliquid oxygen or liquid nitrogen is taken from a place of bulk storageand transferred to a dewar by which the cryogenic fluid is transportedto a place of use and drawn upon as required. The dewar 19 is a doublewalled insulated container comprised of spaced apart inner and outerwalls 11 and 12. Inner wall 11 defines the interior storage compartmentof the container, a space herein indicated at 13. A relatively smalldiameter mouth 14 at the upper end of the dewar provides an entrance toand exit from interior space 13.

The illustrative concept of the invention provides 21 body 15, an end ofwhich seats on the reduced diameter upper end of the dewar 10 in aclosing relation thereto. Thus, outer wall 12 receives the end of body15 in an interfitting relation and is suitably secured thereto, as bywelding. The inner wall 11 is received in a recess 16 in the end of body15 and similarly is secured, as by welding, to the body. The spacebetween the walls 11 and 12 accordingly is effectively closed. The mouth14 communicates with space 16.

The body 15 has a through longitudinal bore 17. At what may beconsidered the upper end of the body, or that end remote from recess 16,a counterbore 18 is formed. A threaded bushing 19 is installed in toclose the upper end of counterbore 18. An interiorly threaded portion 21of the bushing 19 provides a place of mounting for a combination sealand bearing element 22. A rod 23 has a sliding bearing in element 22 andextends downwardly through the bore 17 of body 15 into container space13. The rod 23 is a level indicator and is adapted selectively to becapable of relative vertical movement in the assembly comprising dewar111 and body 15. A housing 24 is secured to the upper end of body 15 bybolts 25 and extends upward in a closed, surrounding relation to rod 23in a manner which it is unnecessary here to consider. A tube 26 ismounted at its ends in the body 15 and in the bushing 19 and provides anenclosure for the rod 23.

A portion of the body 15 between its ends is constructed as an interiorchamber 27. Integrally formed in the wall of the chamber 27 is a helicalpassageway 28. An upper end of passage 28 communicates with a lateral,through opening 29 in the side of the body wall. A lower end thereof isturned longitudinally downward in radially offset relation to the bodyaxis and opens into recess 16. A pipe 31 is installed in opening 29 andprovides a combined fill and draw off means. A valve 32 is interposed inpipe 31 and is manually adjustable to an open and to a closed positionwith respect to flow through the pipe. At the lower end of passage 28, atube 33 has one end extending through recess 16 to be received in andcommunicate with passage 28. The tube 33 extends vertically downwardinto container space 13 and may advantageously project to a point nearthe bottom of such space.

The body chamber 27 is connected to counterbore 18 by a curving interiorbody surface 34 which expands as it extends toward counterbore 18 todefine a conical surface 35. Curving surface 34 defines with theexterior of tube 26 a restricted flow passage 36. The surface 35provides a seat for a valve 37 which surrounds tube 26 and in seating onsurface 35 effectively closes passage 36. A compression spring 38 seatson the bushing 19 and urges valve 37 normally closed.

The body chamber 27 communicates at its lower end with the recess 16,and thereby with container space 13, through an opening 39. The upperpart of the chamber 27 communicates with one end of a curving passage41, the other end of which opens through conical surface 35. Thedescribed other end of passage 1 is closed in a seated position of valve37 and opened in a raised or open position of the valve. Opening 39 andpassage 4-1 are connected by a tube 42.

The body 15 has circumferentially spaced apart radiai openings 43 and 3dcommunicating at their inner ends with counterbore 18. Installed in toclose opening 43 is a fitting d incorporating a rupture disc (notshown). A pipe 40 is screwed into opening 44 and extends to atmosphereor to a suitable place of vent. A manual valve 46 is interposed in pipe45 and is altematively adjustable to open and close such pipe to a flowof fluid therethrough. The counterbore 18 is further connected to ventor to the atmosphere by other, pressure responsive, means, and, forconvenience of illustration, this has been shown diagrammatically as aline 47 incorporating a pressure relief valve 43 and communicating withpipe 4% in advance of valve 46.

The cryogenic fluid is in storage maintained under pressure and in asubstantially saturated condition. In the transfer operation, fromstorage to a dewar, use is made of the inherently pressurized conditionof the fluid or pumps are utilized. ln either event, the fluid reachesthe body as a two-phase fluid comprising whole liquid and entrainedgases or vapors. Pressure reduction produces a gas in the fluid. Also,warming of the fluid which is a necessary result of directing it throughpipe lines and passages to the dewar, releases vapors.

The opening 29 has a non-radial disposition. It aligns tangentially ofchamber 27 or more particularly of helical passage 28 therein. Inentering passage 28, therefore, the two-phase fluid supplied throughpipe 31 goes into a swirling movement producing results characteristicof a centrifugal separator. Heavy liquid particles go to and remain inthe outside of passage 28 while lighter vapors and gases separate fromthe liquid and move toward the center of chamber 27 where they risealong the exterior of tube 26 to and through passage 36. A pressuredifference across valve 37 is established, causing this valve to raiseto an open position, substantially as shown in FIG. 2 of the drawings.An open flow passage accordingly is defined from chamber 27 throughpassage 36 into counterbore 28 and out passage 44 to and through ventpipe 40. The clevaporized liquid continues in its path through passage28 and discharges therefrom into tube 33 to be conducted thereby tocontainer space 13, the tube 33 terminating as before indicated at anyselected level within the container space. The unseating of valve 37opens the passageway defined by opening 39, passage 41!. and tube 42,which passageway communicates through the open mouth 14 of dewar wall 11with the container space 13 in the upper part thereof. Accordingly,vapors released Within space 33 and rising to the top thereof are freeto join the centrifugally separated gases and exit through vent pipe 45.The arrangement is such that the cryogenic fluid enters tube 33 in asaturated condition and flows at a higher mass flow rate than would bethe case if it were in the form of surface 35 leading upwardly therefromform a passageway having the characteristics of a venturi. The locationof passage 41 is such that it and communicating spaces are subjected toan education influence as centrifugally separated vapors rise throughthe passage 36 and expand into the continuation thereof defined byconical surface 35. The education effect, exerted upon the upper part ofcontainer space 13 assists in the exhausting of this space of releasedvapors.

In a fluid transfer operation, manual vent valve 46 is opened and themanual fill-drawoff control valve 32 is open. The two-phase fluid, asrepresented by the stippled arrows 49 is free to flow through pipe 31into helical passage 28. Saturated liquid, represented by solid arrows51 reaches tube 33 and is directed thereby toward the bottom ofcontainer space 13. Released vapors, as represented by open arrows 52flow to vent pipe 40 by way of venturi passage 36 and by way of tube 32.When filling is complete, both valve 32 and manual vent valve 46 areclosed. Pressure in the dewar, which is function of the continuingattempted expansion of the cryogenic fluid, equalizes in chamber 27 andin counterbore 18 whereupon valve 37 closes. When it is desired to drawoff liquid from the dewar valve 32 is opened. Internal pressure forcesliquid from the space 13 upward through tube 33 and through chamber 27to opening 29 and pipe 31 which at this time assume the character ofoutlets for the discharging liquid.

lf, while the liquid is stored in dewar 10, internal pressures rise toan undesirable height, valve 48 relieves to vent excess pressure. Therupture disc in fitting 45 serves a similar function in the event valve48 is inoperative or unable to vent pressure at a desired rate.

Used with unpressurized liquid containers, the device of the inventionwould omit valve 37 and may omit vent valve 46. Released gases wouldflow directly to the atmosphere or place of venting.

It is evident, moreover, that the device provides a phase separator ofgeneral utility, structural details of which may vary substantiallywithin the broad concept characterizing the invention.

The invention allows rapid filling of closed containers with saturatedliquid. It is of maximum advantage when the source fluid is composed ofboth liquid and gas phases. Its most apparent application is in thefiling of dewars with cryogenic fluids. However it will function withother fluids, and can be used to eX- tract liquid samples from a twophase stream of fluid. A device according to the invention will normallybe used to fill vessels with liquid from a source which is at a pressureabove ambient.

in the illustrative embodiment of the invention, it has been assumedthat vapor rise through opening 36 is a primary flow while thatdischarging from space 13 through tube 42 is a secondary flow. Shouldconditions be such that the reverse is true, then the structure of body15 may appropriately be revised for a reverse venturi effect. Forexample, level indicator 23 could be omitted or relocated, the upper endof tube 26 flared outward in the manner of surface 35, with radialopenings at the base of such surface communicating with counterbore i8,and a plug valve biased to close flow through the tube past such radialopenings. The vent connection would be beyond the plug valve. The

connection 39, 41, 42 would be omitted, with vapor flow out of the dewarbeing by way of tube 26. Venting of vapor released from fluid in helicalpath 28 would be by way of the described radial openings in tube 26,influenced by the primary flow thereby.

What is claimed is: r

1. A device for separating vapor phase fluid from a flowing liquid,including a body providing a flow path for the liquid in whichcentrifugal forces are utilized for a release of vapor phase fluid witha directed escape thereof through a vapor phase flow passage to a vaporoutlet, a separate vapor flow passage in said body leading to saidoutlet, and means utilizing vapor flow through one of said passages toinduce flow in the other passage.

2. A device according to claim 1, wherein the first said flow passageincludes venturi means and .wherein said separate flow passagecommunicates with said first flow passage in position to be evacuated byflow through said venturi means.

3. A device according to claim 1, wherein said body provides a liquidinlet and an internal helical path terminating in a discharge opening atone end thereof, the first said flow passage forming venturi meanscentrally of said helical path through which vapor phase fluid releasedfrom liquid in said helical path escapes, said separate vapor flowpassage opening through said one end of said body and leading to thefirst said flow passage at a location to have flow therethroughinfluenced by flow through said venturi means.

4. A device according to claim 3, wherein said helical flow path isformed in a first chamber in said body, a second chamber therein beinglongitudinally spaced from the first chamber and connected thereto bysaid venturi means, said vapor outlet communicating with said secondchamber, and an opening in said body communicating with the first saidchamber for admitting liquid to said helical path.

5. A device according to claim 4, characterized in that said device isuseful on and in connection with a vessel, said discharge opening andthe said separate flow passage communicating through said one end ofsaid body with the vessel interior.

6. A device according to claim 5, characterized by a spring loaded valvenormally seated in to close said venturi means and opening underreleased vapor pressure in said first chamber, said separate vapor flowpassage extending to said venturi means in position to be closed by saidvalve when seated therein.

7. A device useful in the liquid filling of vessels to facilitateseparation and removal of fluid in the vapor phase, including a bodyadapted to mount on to be a part of a vessel, said body providing a flowpath for incoming fill liquid in which entrained vapors are inherentlyreleased and having an outlet through which such released vapor escapesprior to reaching said was sel, and means utilizing escaping vaporreleased in said flow path to induce vapor flow from the vesselinterior.

8. A device according to claim 7, characterized by pressure responsivevalve means intermediate said flow path and said vapor outletrestricting escape of released vapors.

9. A liquid container of rapid fill characteristics, including acontainer having a mouth through which it is filled and throlgh whichcontained liquid is drawn off a body installe in a closing relation tosaid mouth and having a liquid flow passage for fill and draw off, meansin said passage way imparting a centrifugal effect to incoming liquidfor a release of vapor phase fluids therefrom, and means in said bodyproviding for escape therefrom of released vapor phase fluid prior toreaching said container.

10. A liquid container according to claim 9, characterized by a valvebiased to restrict escape of vapor phase fluids for a pressurizing ofthe container interior.

11. A liquid container according to claim 9, characterized by a separateflow passage way intercommunicating said last named means and the vesselinterior providing for the escape of vapor phase fluids released in thecontainer.

1. A device for separating vapor phase fluid from a flowing liquid,including a body providing a flow path for the liquid in whichcentrifugal forces are utilized for a release of vapor phase fluid witha directed escape thereof through a vapor phase flow passage to a vaporoutlet, a separate vapor flow passage in said body leading to saidoutlet, and means utilizing vapor flow through one of said passages toinduce flow in the other passage.
 2. A device according to claim 1,wherein the first said flow passage includes venturi means and whereinsaid separate flow passage communicates with said first flow passage inposition to be evacuated by flow through said venturi means.
 3. A deviceaccording to claim 1, wherein said body provides a liquid inlet and aninternal helical path terminating in a discharge opening at one endthereof, the first said flow passage forming venturi means centrally ofsaid helical path through which vapor phase fluid released from liquidin said helical path escapes, said separate vapor flow passage openingthrough said one end of said body and leading to the first said flowpassage at a location to have flow therethrough influenced by flowthrough said venturi means.
 4. A device according to claim 3, whereinsaid helical flow path is formed in a first chamber in said body, asecond chamber therein being longitudinally spaced from the firstchamber and connected thereto by said venturi means, said vapor outletcommunicating with said second chamBer, and an opening in said bodycommunicating with the first said chamber for admitting liquid to saidhelical path.
 5. A device according to claim 4, characterized in thatsaid device is useful on and in connection with a vessel, said dischargeopening and the said separate flow passage communicating through saidone end of said body with the vessel interior.
 6. A device according toclaim 5, characterized by a spring loaded valve normally seated in toclose said venturi means and opening under released vapor pressure insaid first chamber, said separate vapor flow passage extending to saidventuri means in position to be closed by said valve when seatedtherein.
 7. A device useful in the liquid filling of vessels tofacilitate separation and removal of fluid in the vapor phase, includinga body adapted to mount on to be a part of a vessel, said body providinga flow path for in-coming fill liquid in which entrained vapors areinherently released and having an outlet through which such releasedvapor escapes prior to reaching said vessel, and means utilizingescaping vapor released in said flow path to induce vapor flow from thevessel interior.
 8. A device according to claim 7, characterized bypressure responsive valve means intermediate said flow path and saidvapor outlet restricting escape of released vapors.
 9. A liquidcontainer of rapid fill characteristics, including a container having amouth through which it is filled and through which contained liquid isdrawn off, a body installed in a closing relation to said mouth andhaving a liquid flow passage for fill and draw off, means in saidpassage way imparting a centrifugal effect to in-coming liquid for arelease of vapor phase fluids therefrom, and means in said bodyproviding for escape therefrom of released vapor phase fluid prior toreaching said container.
 10. A liquid container according to claim 9,characterized by a valve biased to restrict escape of vapor phase fluidsfor a pressurizing of the container interior.
 11. A liquid containeraccording to claim 9, characterized by a separate flow passage wayintercommunicating said last named means and the vessel interiorproviding for the escape of vapor phase fluids released in thecontainer.